SSC CHSL Topic Wise Study Material – General Awareness – Environment and Ecology
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This section is an essential segment of the General Awareness. In the beginning, the questions of this section were used to be included under the section of Geography but nowadays this is used to be incorporated as an individual subject. The questions asked from this section are related to the Environment, Ecology System, Pollution, Global Warming, Ozone Depletion, Bio-diversity, Water Management, Conservation Activities, etc.
1. The serious environmental degradation of Maldives is considered to be essentially due to SSC (10 + 2) 2015
(a) high population density
(b) industrial pollution of water and air
(c) constant soil erosion
(d) None of the above
2. ‘Red Data Book’ provides an account of SSC (10 + 2) 2015
(a) Extinct animals
(b) Endangered plants and animals
(c) Endangered plants
(d) Fossil plants
3. Which one of the following contains maximum percentage of carbon? SSC (10 + 2) 2014
(a) Wrought iron
(b) High speed steel
(c) Cast iron
(d) Stainless steel
4. Which of the following appeared to be with a significant potential for accumulation through food chains? SSC (10 + 2) 2014
5. Which of the following is the largest Biosphere Reserves of India? SSC (10 + 2) 2014
(d) Gulf of Mannar
6. About how much of the world’s land area is tropical rainforest? SSC (10 + 2) 2014
7. According to your text, what can “be thought of as the genetic library that keeps life going on Earth”? SSC (10 + 2) 2014
(a) A bio-engineering lab
(b) Human genes
(c) The human genome project
8. In which Eco-system Grassland is included? SSC (10 + 2) 2013
9. The depletion of Ozone layer is mainly due to SSC (10 + 2)2013
(a) aviation fuels
(b) radioactive rays
(d) valcanic eruptions
10. The main advantage of Rain Water Harvesting (RWH) is SSC (10 + 2)2013
(a) avoid floods
(b) reduce the loss of water
(c) avoid soil erosion
(d) recharge ground water
The natural surroundings like air, water, land, atmosphere etc are also part of the physical environment but they are commonly known as natural environment. People surrounding the components of environment are known as human environment. It is also known as the social environment and includes elements like the religious and emotional relations.
Types of Environment
There are mainly three types environment
1. Physical Environment
2. Biotic Environment
3. Social or cultural Environment
Atmosphere is relatively thin layer of odourless, tasteless and colourless gases (air) and dust surrounding the Earth. It’s dry gas comprises 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.03% carbon dioxide and tiny proportions of neon, krypton, helium, methane, xenon, hydrogen and ozone, together with water vapour, which values between 0 and 4%.
Atmosphere also consist of Particulate Matter (PM), which are solid particulates or liquid droplets suspended in the atmosphere. Increasing environment concerns are making classification and role of particulate matter is important.
Classification of Particulate Matter
It can be classified as
Dust Particles of different size and irregular shapes which either are suspend or floating through the air.
Smoke Incomplete combustion of coal and wood suspends very fine particles into the air.
Soot Badger size carbon particles impregnated with tar, suspended into the air.
Aerosols Suspended minute particles acting as a dust veil, they cover the amount of solar radiation reaching the Earth, therefore counteract greenhouse gas effect.
Haze Caused by very fine dust in atmosphere.
Mist Suspension of liquid droplets formed after condensation of vapours.
Fumes Condensation of gaseous particles.
* Carbon sink is a natural or artificial reservoir that accumulates and stores some carbon containing chemical compounds for an indefinite period.
* A person breathes 22000 time a day inhaling about 16 kg of air.
* Repairable Suspended Particulate Matter (RSPM) are the particulates having diameter less than 10pm. These are very small particles and as such could be inhaled. Concentration of RSPM is highest in Vadodara.
Ecology and Ecosystem
The term ecosystem was first used by AG Tansley in 1935, who defined ecosystem as a particular category of physical system, consisting of organisms and inorganic components in a relatively stable equilibrium, open and of various sizes and kinds.
In an ecosystem, the biotic and abiotic components are inseparably inter- related and interact with each other. Being an open system, an ecosystem has energy and material flowing across its boundaries.
The process by which a producer converts energy from the Sun, along with carbon dioxide (C02) and water (H20), to sugar (glucose) and oxygen (02). Photosynthesis is the primary means of production in most ecosystems.
Another, less common form of production that relies on energy from chemicals, rather than solar energy, to create organic energy resources.
Functions of Ecosystem
The main functions of an ecosystem are
» Materials or nutrient cycle.
» Biological or ecological regulation including both regulation of organisms by environment and regulation of environment by the organisms.
The feeding of one organism upon another in a sequence of food transfer is known as a food chain. Another definition is ‘the chain of transfer of energy’ (which typically comes from the Sun) from one organism to another. A simple food chain is like the following. Grass > Insect > Frogs > Snake > Hawk
In this food chain, the grass is the primary producer. The insects are the primary consumers because they depend upon grass for food. The frog is the primary consumer because it eats the insects. The snake, a secondary carnivore, eats the frog. The hawk is the tertiary carnivore because it eats the secondary carnivore, the snake. The hawk eventually dies and its remains are broken down by decay-causing bacteria and fungi. Except in deep-sea hydrothermal ecosystems, all food chains start with photosynthesis and will end with decay.
Trophic levels are the feeding position in a food chain such as primary producers, herbivore, primary carnivore, etc. Generally, green plants form the first trophic level, the producers. Herbivores form the second trophic level, while carnivores and omnivores form the third and even the fourth trophic levels. Trophic level classification is one of the function and not of the population
A network of food chains or feeding relationships by which energy and nutrients are passed on from one species of living organism to another is called food web.
A food web is represented by a graphical description of feeding relationships among species in an ecological community, e.g., of who eats whom. It is also a means of showing how energy and materials (e.g., carbon) flow through a community of species as a result of these feeding relationships.
Nutrient Flow in Ecosystem
Every ecosystem has several interrelated mechanisms that affect human life. These are the water cycle, carbon cycle, the oxygen cycle, the nitrogen cycle and the energy cycle. While every ecosystem is controlled by these cycles, in each ecosystem its abiotic and biotic features are distinct from each other.
A forest may be defined as large area, mostly uninhabited by human beings but covered by different type of vegetation (flora) and a home to wide variety of animals (fauna).
Deforestation is defined as the reckless felling of trees by human beings for their ulterior ends.
Causes of Deforestation
Causes of the deforestation are
» Shifting cultivation
» Overgrazing and conversion of forests to pasture for domestic animals
» Wood used as fuel
» Commercial logging
» Mining, quarrying and irrigation and industrial products
» Government sponsored programmes that resettle landless farmers
Effects of Deforestation
» Soil erosion
» Social upheavels
» Decrease in rainfall
» Lowering of water table
» Loss of biodiversity
Conservation and Management of Forests
Scientific management of forests is necessary for their sustainable exploitation. Following measures could be adopted for the conservation and management of forests.
Afforestation and Reforestation
Trees could be planted on land, which was formerly not under plant cover, to make a forest for commercial or other purposes under afforestation.
Protection of Forests
Forest can be protected through following ways
» By demarcating regions and type of forest growth.
» Reserving forests as protected areas.
» Forests should be cultivated on flat land.
» Rapid growth of population should be checked.
» Unholy nexus between timber Mafias and corrupt officials should be uprooted e.g., Chipko Movement.
» Surveillance through information technology.
» Social forestry is preservation of green cover and economic benefits for participating community.
National Forest Policy
India is one of few countries which has a forest policy since 1894. Policy revision took place in 1952 and again in 1988. Philosophy behind policy of 1988 is protection, conservation and development of forest sand to increase the total forest cover up to 33%.
National Forest Commission
First National Forest Commission was set up in 2003, under Justice BN Kirpal tasks in front of committees are to review and assess the existing forest policy and legal framework and their impact from the ecological, scientific, economic, > social and cultural points of view. Committee recommended by taking specific policy options for achieving sustainable forest and wildlife management and development, biodiversity conservation and ecological security, besides suggesting ways and means to make administration more effective to achieve policy goals.
Problems Faced by Indian Forests
» No uniform stand in forest growth.
» Uneven distribution of forest.
» Low productivity of forests .
» Inaccessibility of forests.
» Increased pressure from live stock population.
» Under employment in forest (70 million tribal and 200 million non-tribal population is dependent on forest).
Biodiversity, simply is a variety of life. Biodiversity means the variability among living organisms from all’ sources including, terrestrial, marine and other aquatic ecosystem and the ecological complexes of which they are part. It is clear that Biodiversity is essentially a synonym of Life on Earth.
Levels of Biodiversity
Biodiversity is explained through genes,species and ecosystem, which correspond to three Fundamental and Hierarchically related levels of Biodiversity.
Gene Pool Centres
Gene pool is defined as stock of genes found in an inter breeding population. Gene pool centres refer to areas on the Earth which are seen as places where important crop plants and domestical animals organised. Gene pool is variation of genes within species.
It involves two aspects
Various population of each species i.e., thousands of rice varieties available in India.
Genetic variation within each populations i.e., high genetic variation among Indian Rhinos.
* Currently the rate of the extinction of species is 1000 times the natural rate and it is estimated that 34000 plant and 5200 animal species face extinction in future.
* According to International Union for Conservation of Nature (IUCN), the monetary value of goods and services that are provided by ecosystems is estimated to be US $33 trillion year.
* Some 3000 whole bush land ecosystems in Australia which are disappearing taking more than 1500 species with them.
* Over 50% of world’s plant species and 42% of all terrestrial vertebrate species are endemic to just 34 biodiversity hotspots.
* Madagascar is considered a biodiversity hotspot having maximum concentration of floral and faunal species on this Earth.
* Less than 8% of all grasslands worldwide are protected.
* 35% of world’s mangrove area over from 12th Century.
International Conventions on Wildlife
India is a party to five major international conventions related to wildlife conservation, which are given below. The Ministry of Environment and Forest is the nodal agency for these conventions.
World Wide Fund for Nature (WWF)
The World Wide Fund for Nature (WWF) is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. It is the world’s largest independent conservation, organization with over 5 million supporters worldwide, working in more than 100 countries, supporting around 1300 conservation and environmental projects.
The group says its mission is “to halt and reverse the destruction of our environment”. Currently, much of its work focuses on the conservation of three biomes that contain most of the world’s biodiversity: forests, freshwater ecosystems, oceans and coasts. Among other issues, it is also concerned with endangered species, pollution and climate change.
The Giant Panda mascot of WWF originated from a panda named Chi Chi that was transferred from the Beijing Zoo to the London Zoo in the same year of the establishment of WWF.
Earth Hour is a worldwide event organised by the World Wildlife Fund (WWF) and held towards the end of March annually, encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change. The event, conceived by WWF and Leo Burnett, first took place in 2007, when 2.2 million residents of Sydney participated by turning off all.non-essential lights. Following Sydney’s lead, many other cities around the world adopted the event in 2008. Earth Hour 2012 took place on 31 March, 2012 from 8:30 pm to 9:30 pm, at participants local time.
Biodiversity hotspots are defined as areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat. Species are described as endemic if they are unique to a specific area or region and don’t naturally occur anywhere else. Due to their limited ranges, endemic species are particularly vulnerable to extinction.
The biodiversity hotspots concept was first proposed by Norman Myers in 1988. Since then, the hotspots have been reassessed and updated and there are currently 25 hotspots. Because of the large number of species under threat and lack of conservation funding it is economically unfeasible to protect them all; areas must be given priority for conservation.
The hotspots concept aims to protect the greatest number of species at the least cost. The 25 hotspots contain 44% of all vascular plant species and 35% of terrestrial vertebrates and encompass only 1.4% of the Earth’s surface. However, collectively they have lost 88% of their original primary vegetation. Species in these areas are at risk from extinction if further habitat loss occurs.
Biodiversity Hotspots in India
Hotspots are areas which are extremely rich in species, “having high endemism and face a constant threat. There are 25 hotspots in the world and in India there exist two hotspots, the Western Ghats and the Indo-Myanmar region (covers the Eastern Himalayas).
The Eastern Himalayas display an ultra varied topography which fosters species diversity and endemism. In Sikkim within an area of 7298 km, 2250 of 4250 plant species are endemic. The forest cover is Eastern Himalaya has shrunk from 340000 to 110000 km2 despite the loss. The region is home to some botanical rarities. The region is the meeting ground of the Indo-Malayan and Indo-Chinese biogeographical realms as well as the Himalayan and Peninsular Indian elements.
Western ghats and Sri Lanka biodiversity hotspot covers an area of 160000 km2. Around 5916 species are found in this region and around 235 local floral species are endangered species. The region covers Western ghats in Maharashtra, Karnataka, Tamil Nadu and Kerala. There are two main centres of diversity, Agastyamalai hills and the Silent valley.
Biodiversity in India
India is one, of the 12 mega diverse countries of the world. With only 2.5% of land area, India already accounts for 7.8% of global recorded species. This is owing to the country’s tropical location, varied climate and physical features. India’s unique biogeographical composition has living elements from three major biogeographic realms. The Indo-Malayan, which is the world’s richest realm, the agro-tropical and the Eurasian. Much of India’s diversity is found in forests. Where India’s flora is concerned, there are about 46000 species of plants, which comes to about 7% of world’s total. About 33% of these are endemic. There are 15000 flowering plants, which is 6% of world’s total. Roughly 1500 plant species are endangered.
India has about 81000 animal species, representing about 6.5% of world’s fauna. These include 60000 insect species, 2456 fish species, 1230 bird species, 372 mammals, over 440 reptiles and 200 amphibians with largest concentration in Western Ghats and 5000 molluscs.
Livestock diversity is high. There are 400 breeds of sheep, 27 of cattle and 22 of goats found in India.
Classification of Biodiversity in India
Malayan Biodiversity It is found along the densely forested areas of the Eastern Himalayas and along the coastal areas.
Ethiopian Biodiversity The arid and semi-arid regions of Rajasthan are characterised by this kind of biodiversity.
European Biodiversity This kind of biodiversity is found in the areas of upper Himalayas, where the climatic character is mostly temperate in nature.
Indian Biodiversity The dense forest areas of Indian plain are characterised by this kind of forest.
Though Biodiversity losses are not quantified the Wildlife Act mentions 253 fauna species as requiring adequate protection and 135 plant species have been identified as endangered by Botanical Survey of India.
Efforts to Protect Indian Biodiversity
It was started by Government of India on 1st April, 1973 in Corbett National Park as a consequence of the concrete international effort to create an awareness and raise funds for the saving of tiger. Tiger reserves were established under this project.
Poaching for elephant tusks has endangered the species, especially in Southern India. Project Elephant was launched in February 1992 to assist stales having tree ranging population of wild elephants to ensure long term survival of identified viable population of elephants in their natural habitat.
In May 2006, Government of India, initiated preventive action to curb further decline in the population of vultures which included banning of diclofenac in veterinary sector.
Project Snow Leopard
The Project Snow Leopard was started on the lines of Project Elephant, Project Tiger and Project Rhino by the Ministry of Environment and forests in 2006. India is believed to have between 400 and 700 show leopards is the five Himalayan States, Jammu and Kashmir, Himachal Pradesh, Uttarak- hand, Sikkim and Arunachal Pradesh. The Project aims to conserve and protect the highly endangered species in it’s natural habitat.
The one homed Rhino is found in India only. The population of Rhinos is highly threatened by illegal poaching for it’s horn, which is highly valued as an aphrodisiac in grey markets. The Project Rhino was initiated in 1987. Kaziranga and Manas in Asom and Jaldapara Paschim Banga are the main habitats of Rhinos.
Saurashtra Peninsula in Gujarat is the only home to Asian lions. The Government of Gujarat initiated this project in 1972.
Hangul is a deer of the species of European Reindeer. Hangul is extinct throughout the world except a small population left in Dachigam National Park in Kashmir. Hangul is listed in the Red data book of IUCN. To conserve the dwindling population, the Project Hangul was started in 1970.
Crocodile Breeding Scheme
The fast dwindling population of crocodile forced Government of India to start Crocodile Breeding Scheme in 1975 with the help of UNDP. Tikarpara in Odisha was chosen to launch the project, later the scheme was xtended to Rajasthan, Madhya Pradesh, Kukail in Uttar Pradesh, Maharashtra, Andaman, Asom, Bihar and Nagaland.
Project Red Panda
Red Panda is found, in the Eastern Himalayan region of India at a height between 1500 m and 4000 m.
In Arunachal Pradesh, it is known as Cat Bear. The Project was started in 1966 at Padmaja Naidu Himalayan Wild Life Park with the did of WWG. Red Panda is found in Arunachal Pradesh, Sikkim and Darjeeling region in Paschim Banga.
Project Manipur Thamin
South-East part of lake Lokatak in Manipur is home to Thamin deer. It is enlisted among the rarest species of mammals. It’s population slipped to mere 18 in 1977. To conserve and increase the population project Thamin was launched in 1977 in Manipur.
Project Olive Ridley Turtles
The dwindling population of Olive Ridley Turtles made the Government of Odisha start the project in 1975.
The project was launched at Bhitarkanika in Cuttack district. Bhitarkanika is. second largest Mangrove forest. The project even extends to the Rushikulya and mouth of river Devi.
Pollution is defined as presence of abnormally high concentrations of harmful substances in the environment, often put there by people. But more scientific definition of pollution could be given as it is typical case of a resource out of place.
Problem of pollution arises from the, presence of a resource in system which is ill-adapted to it resulting in termination of some and initiation of other biological processes altering structure of species and thus changing dynamics and development of ecosystem.
Central Pollution Control- Board (CPCB) is autonomously body of environment ministry and is nodal agency for controlling the water pollution.
It coordinates the activities of State Pollution Control Board (SPCB) and pollution control committees. Water (Prevention and Control of Pollution) Act, 1974 regulates water quality through pollution control boards.
CPCB has nationwide network for water quality monitoring comprising 1019 stations in 28 States and 7 UTs. CPCB sees the monitoring level in a three7 tier system. First tier caters to the needs of Global Environment Monitoring System (GEMS). In Tier-2 water quality is monitored under the national programme, Monitoring of Indian National Aquqtic Resources (MINARs). At Tier-3, water quality is monitored at State level.
Pollutants are substances which cause pollution and they could be in any form solid, liquid or gaseous.
Types of Pollutants
A primary pollutant is an air pollutant emitted directly from a source. A secondary pollutant is not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere.
Primary pollutants are those pollutants which are directly available in the atmosphere such as C02, CO, S02.
1. Sulphur dioxide (S02) produced from burning of coal mainly in thermal power plants. It causes smog and acid rain.
2. Nitrogen oxides (NO2)causes smog and acid rain. It is produced from burning fuels including petrol, diesel and coal.
3. Carbon monoxide (CO) is a product by incomplete combustion of fuel such as natural gas, coal or wood.
4. Chlorofluoro carbons (CFCs), released mainly from refrigeration. These gases combine with few other gases, which leads to a reduction of the ozone layer that protects the Earth from the harmful ultraviolet rays of the Sun.
5. Carbon dioxide (CO2), a greenhouse gas emitted from combustion.
6. Suspended Particulate Matter (SPM), include smoke, dust and vapour that can remain suspended for extended periods and can be introduced in the environment as primary as well as secondary pollutants.
7. Toxin metals, such as dead, cadmium and copper can enter to the environment through petrol, hair dye products, paints, batteries etc,
8. Volatile Organic Compounds (VOC), such as hydrocarbon fuel vapours and solvents.
9. Ammonia (NH3) emitted from agricultural processes.
Secondary pollutants are derived from primary pollutants.
The examples of secondary pollutants are
1. Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog, such as nitrogen dioxide.
2. Ground level ozone (03) formed from NO and VOCs.
3. Peroxyacetyl Nitrate (PAN) similarly formed from N02 and VOCs.
The United Nations Environment Programme (UNEP) has arranged different types of pollutants according to the order of priority as mentioned below
» Non-point source pollution does not have one specific source, Such as a factory. Non-point source pollution comes from the cumulative effect of a region’s residents going about their everyday activities, such as fertilising a lawn or driving a car.
Presence of contaminants released by human activities into the Earth’s atmosphere having potential of causing harm to property or the precious lives of plants, animals or humans.
Causes and Sources
Air pollution is caused by various type of pollutants. Petroleum refineries release poisonous gases like sulphur dioxide, nitrogen oxides etc.
Dust is produced from cement factories as stone crushers and hot mix plant release suspended particulate matter more than five times the safety limits by industrial standards. The thermal power plant produce deadly pollutants such as fly ash, S02, hydrocarbons etc. In urban areas, automobiles are the chief sources of pollution.
The ever increasing traffic density has aggravated the existing problem, of air pollution. Automobiles mainly produce pollutants like unburnt hydrocarbons, C02, N02, lead oxides etc. Effect of air pollution could be gauged from the fact that National Environmental Engineering Research Institute (NEERl) observed 50% of residents of Kolkata are suffering ijrom respiratory diseases.
Acid rain is a broad term referring to a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal, amounts of nitric and sulphuric acids. The precursors, or chemical forerunners, of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulphur dioxide (S02) and nitrogen dioxides (N02)resulting from fossil fuel combustion. Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. The result is a mild solution of sulphuric acid and nitric acid. When sulphur dioxide and nitrogen oxides are released from power plants and other sources, prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles.
Bhopal Gas Tragedy, where methyl-iso-cyanate was released in environment, which is a known Toxicant, is also an incident of toxication of environment. Innocuous looking presence of plastic has also introduced toxicity in our food chain. Recent incident of fatality among children due to introduction of toxicity in their system through the use of plastic toys was also an example of toxication.
Control/Measures of Air Pollution
* Suitable fuel selection
* Modification in industrial processes
* Correct selection of manufacturing sites
* More efficient engines
* Euro-Emission Norms Euro 1 and Euro 2 names are given to emission names for new petrol and diesel driven vehicles. Extents of emission of CO, HC,N02 and particulate matter have been specified in terms of gm/km.
Noise is defined as unwanted sound. Sound, which pleases the listeners, is music and that which causes pain and annoyance is noise. At times, what is music for some can be noise for others. Noise can be described as sound without agreeable musical quality or as an unwanted or undesired sound. Thus, noise can be taken as a group of laud, non-harmonious sounds or vibrations that are unpleasant and irritating to ear.
Measurement of Noise Pollution
A decibel is the standard for the measurement of noise. The zero on a decibel scale is at the threshold of hearing, the lowest sound pressure that can be heard. On the scale according to smith, 20 db is whisper, 40 db in the noise in a quiet office. 60 db is normal conversation, 80 db is the level at which sound becomes physically painful.
Radioactive pollution, like any other kind of pollution, is the release of something unwanted into the environment and, in this case, the unwanted thing is radioactive material.
Radioactive pollution can be a very dangerous thing because radiation mutates DNA, causing abnormal growth and possibly cancer, and this radiation remains in the atmosphere for years, slowly diminishing over time. There are many causes of radioactive pollution, which can significantly harm the environment. There are techniques used to manage this pollution, however, we are far from keeping our planet clean of
According to definition of WHO, water pollution occurs when foreign materials either from natural or other sources are added to water supplies and may be harmful to life, because of their toxicity, reduction of normal oxygen level of water, aesthetically unsuitable effects and spread of epidemic diseases.
Sources of Water Pollution
» Sources of water pollution are
» Industrial effluents
» Industrial wastes derived from chemical industries, thermal power plants and nuclear power stations
» Sewage and other waste
» Agricultural discharges
Types of Water Pollution
Water Pollution can be classified as
Surface Water Pollution
Rivers, lakes and ponds constitute surface water.
Three major sources polluting surface water are
» Pesticides and insecticides.
» Toxic metals like lead, mercury, calcium, asbestos, zinc etc.
» Radioactive wastes from the processing and use of nuclear fuels such as uranium and thorium.
River pollution poses a serious problem. Urban sewer drainage and industrial affluents are two major sources of river pollution. Soil erosion causes siltation of lakes. Tourism is also one of the reasons of river pollution.
Sea Water Pollution
It occurs near coastal waters due to dumping of pollutants. Pollution at deep sea is caused by leakage of oil due to shipwreck. Oil spills have caused great harm to sea life in recent past.
Ground Water Pollution
Contamination of ground water takes place through pollutants like nitrates, phosphorus, potash, insecticides, pesticides etc. Control of nature and extent of ground water pollution depends on lithology of subsoils, nature of aquifers the amount and nature of aquifers the amount and nature of rainfall and depth of Water table.
Ground water pollution causes diseases like cholera, jaundice, typhoid, dysentiy etc; and it could assume proportion of epidemic. Some of rare diseases like minamata are caused by mercury contamination. It effects soil fertility also.
Arsenic pollution in drinking water has become a vital important in different part of the world. As per WHO, permitted level of Arsenic in drinking water is 0.05 mg/litre of water. Cause of Arsenic pollution is majority attributed to Arsenide pesticide, use lead arsenate as insecticide calcium arsenate, sodium arsenate etc as herbicides and Arsenic contamination also happens during extraction of gold, lead and coal as it is present in its ones. Districts of Paschim Banga and Punjab are found highest in arsenic toxicity.
Effects of Water Pollution
The effects of water pollution are not only devastating to people but also to animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It diminishes the aesthetic quality of lakes and rivers. ’ More seriously, contaminated water ’destroys aquatic life and reduces its reproductive ability. Eventually, it is a hazard to human health.
Nobody can escape the effects of water pollution.
The individual and the community can help minimise water pollution. By simple housekeeping and management practices, the amount of waste generated can be minimised.
Effects of Water Pollution on Human Health
The water we drink is a crucial component for healthy living. Clean water is essential for health. A sufficient supply of fresh, clean drinking water is a fundamental need for all human, yet it has been observed that billions of people around the world are being deprived of clean drinking water.
Possible effects and diseases that can be brought about by Water Pollution
Cholera An infection of the small intestine. The transmission of cholera is primarily through consuming contaminated drinking water or food.
Typhoid Fever A common universal illness spread by the ingestion of food or infected water which has been contaminated with feces of an infected person containing Salmonella Enterica and Serovar Typhi.
Hepatitis A medical condition characterided by the inflammation of the liver and by the presence of inflamed cells in the tissue of the organ.
E-Coli Infections Can be caught by coming in contact with the stools of humans and animals. This can happen when a person drinks water that has been contaminated by feces.
Controlling Water Pollution
Measures to control water pollution are
» Mass social awareness.
» Ground water pollution can be eliminated by maintaining strict restrictions regarding waste disposal.
» Industrial effluents should be effectively recycled so that pollutants are not released in water.
» Radioactivity, chemical and biological pollutants can be removed from water by absorption, electro dialysis, ion-exchange and reverse osmosis methods biotechnology is also hamassed to clear water pollution.
» The Water (Prevention and Control of Pollution) Act was enacted in 1974 to provide for the prevention and control of water pollution, and for the maintaining or restoring of wholesomeness of water in the country. The Act was amended in 1988.
» The Water (Prevention and Control of Pollution) Cess Act was enacted in 1977, to provide for the levy and collection of a cess on water consumed by persons operating and carrying on certain types of industrial activities. This cess is collected with a view to augment the resources of the Central Board and the State Boards for the prevention and control of water pollution constituted under the Water (Prevention and Control of Pollution) Act, 1974. The Act was last amended in 2003.
Soil and Land Pollution
Soil pollution usually results from the disposal of solid and semi-solid wastes in agricultural practises and insanitary habits.
Causes of Soil Pollution
Soil Pollution by Industrial Wastes These pollutants affect and alter the chemical and biological properties of soil. As a result hazardous chemicals enter into food chain.
Soil Pollution by Urban Wastes High population density in urban area and lack of proper wastage disposable facilities is creating huge piles of waste in urban areas.
» Agricultural practises like use of fertilizers pesticides etc is also adding chemical agents in soil.
Control of Soil Pollution
» Use of pesticides should be minimised.
» Use of fertilizers should be judicious.
» Cropping techniques should be improved to prevent growth of weeds.
» Special pits should be selected for dumping wastes.
» Controlled grazing and forest management.
» Wind breaks and wind shield in areas exposed to wind erosin
» Planning of soil binding grasses along banks and slopes prone to rapid erosin.
» Afforestation and reforestation.
Ozone Layer Depletion
Planet Earth has its own natural sunscreen that shields us from the Sun’s damaging ultraviolet radiation. It’s called the ozone layer, a fragile band of gases beginning 15 km above our planet, and reaching up to the 40-km level. Human activities have caused a substantial thinning of this protective covering – not only over the North and South poles, but right over our heads.
Stopping ozone layer depletion is one of the major challenges facing the world today. The. stakes are incredibly high. With less ozone in the atmosphere, more ultraviolet radiation strikes Earth, causing more skin cancer, eye damage, and possible harm to crops.
The Stratospheric Ozone Layer
The ozone layer lies in the stratosphere, in the upper level of our atmosphere. The ozone in it is spread very sparsely. Stratospheric ozone filters out most of the sun’s potentially harmful shortwave ultraviolet (UV) radiation. This ozone has become depleted, due to the release of Such ozone-depleting substances as chlorofluoro carbons (CFCs). When stratospheric ozone is depleted, more UV rays reach the Earth. Exposure to higher amounts of UV radiation could have serious impacts on Human Beings, animals and plants.
The stratospheric ozone layer sometimes gets confused with the ozone lying near the Earth’s surface, known as ground-level ozone. Although some ground-level ozone occurs naturally, most is produced by the reaction of Sunlight with chemicals found mainly in automobile exhaust and gasoline vapours. This human-caused ozone is a key, unhealthy ingredient of smog. Ironically, we have too much ozone at ground level and not enough in the stratosphere.
The Impacts of Ozone Layer Depletion
Stratospheric ozone filters out most of the Sun’s potentially harmful shortwave Ultra Violet (UV) radiation. If this ozone becomes depleted, then more UV rays will reach the Earth. Exposure to higher amounts of UV radiation could have serious impacts on human beings, animals and plants, such as the following
Impact on Human Life
» More skin cancers, sunburns and premature aging of the skin.
» More cataracts, blindness and other eye diseases, UV radiation can damage several parts of the eye, including the lens, cornea, retina and conjunctiva.
» Cataracts (a clouding of the lens) are the major cause of blindness in the world.
» A sustained 10% thinning of the ozone layer is expected to result in almost two million new cases of cataracts per year, globally (Environment Canada, 1993).
» Weakening of the human immune system (immuno suppression). Early findings suggest that too much UV radiation can suppress the human immune system, which may play a role in the development of skin cancer.
» Adverse Impacts on Agriculture, Forestry and Natural Ecosystems
» Several of the world’s major crop species are particularly vulnerable to increased UV, resulting in reduced growth, photosynthesis and flowering. These species include wheat, rice, barley, oats, corn, soybeans, peas, tomatoes, cucumbers, cauliflower, broccoli and carrots.
» The effect of ozone depletion on the Canadian agricultural sector could be significant.
» Only a few commercially important trees have been tested for UV (UV-B) sensitivity, but early results suggest that plant growth, especially in seedlings, is harmed by more intense UV radiation.
Impact on Animals
In domestic animals, UV overe xposure may cause eye and skin cancers. Species of marine animals in their developmental stage (e.g., young fish, shrimp larvae and crab larvae) have been threatened in recent years by the increased UV radiation under the Antarctic ozone hole.
Impact on Materials
Wood, plastic, rubber, fabrics and many construction materials are degraded by UV radiation.
The economic impact of replacing and/or protecting materials could be significant.
The Main Ozone-Depleting Substances (ODS)
Chlorofluoro Carbons (CFCs)
* The most widely used ODS, accounting for over 80% of total stratospheric ozone depletion.
* Used as coolants in refrigerators, freezers and air conditioners in buildings and cars manufactured before 1995.
* Found in industrial solvents, dry-cleaning agents and hospital sterilants.
* Also used in foam products – such as soft-foam padding (e.g.cushions and mattresses) and rigid foam (e.g. home insulation).
Used in some fire extinguishers,’In cases where materials and equipment would be destroyed by water or other fire extinguisher chemicals. In B.C., halons cause greater damage to the ozone layer than do CFCs from automobile air conditioners.
Used mainly in industry – for vapour degreasing, some aerosols, cold cleaning, adhesives and chemical processing
Used in solvents and some fire extinguishers.
Hydrochlorofluoro Carbons (HCFCs)
HCFCs have become major, transitional substitutes for CFCs. They are much less harmful to stratospheric ozone than CFCs are. But HCFCs they still cause some ozone destruction and are potent greenhouse gases.
The average weather conditions at a specific place over a lengthy period of time, generally thirty years, is called climate. So, simply climatic change could be defined as slow variations, of climatic characteristics over time at given place. This may be indicated by geological record in the long term, by changes in the landforms in intermediate terms and by vegetation changes in short term. Small variations in climate can also be observed from the period during which reliable instrumental records have been available, e.g., the increase of C02 and the 1°C warming trend witnessed between 1850 and 1940.
Causes of Climate Change
The causes of climate change can be divided into two categories, human and natural causes. It is now a global concern that the climatic changes occurring today have been speeded up because of man’s activities.
The earth’s climate is influenced and changed through natural causes like volcanic eruptions, ocean current, the earth’s orbital changes and solar variations.
The Industrial Revolution in the 19th century saw the large scale use of fossil fuels for industrial activities. These industries created jobs and over the years, people moved from rural areas to the cities. This trend is continuing even today. More and more land that was covered with vegetation has been cleared to make way for houses. Natural resources are being used extensively for construction, industries, transport and consumption. Consumerism (has increased by leaps and bounds, creating mountains of waste. Also, our population has increased to an incredible extent
Global warming is the rise in the average temperature of Earth’s atmosphere and Oceans since the late 19th Century and its projected continuation. Warming of the climate system is unequivocal, and scientists are quite certain that it is primarily caused by increasing concentration of greenhouse gases produced by human activities such as the burning of fossil fuels and also deforestation.
Causes of Global Warming
Global warming in recent times has resulted in heating up of the atmosphere not as a result of the natural greenhouse effect but as a result of increase in the greenhouse gases C02, methane, nitrous oxide and ozone-in the atmosphere as a result of human activities. What happens is that due to increase in greenhouse gases, the infrared radiation that is absorbed from space as well as part of the outgoing energy that is absorsed and remitted by the gases, increase. So, the atmosphere and the surface warm up. The main greenhouse gases differ in their intensity of heat trapping and in their ability to affect the radioactive balance of the Earth.
The Earth’s climate depends upon the solar radiation factor. Part of outgoing energy is absorbed and re-emitted by radioactive atmospheric gases which are called greenhouse gases. When this absorption and re-emission takes place, the net emission of energy into space is reduced. So, the atmosphere and the surface air will warm on Earth till the outgoing energy equals the incoming energy. This is called the greenhouse effect.
Man Made GHG’s
CFCs While the natural greenhouse gases are showing an increase over the decades, there is also the concern of emission of purely man-made greenhouse gases which include many ozone depleting substances like the CFCs or chlorofluoro carbons.
These are much more potent than the same quantity of carbon dioxide or methane. Additional CFC atoms added to the atmosphere are 10000 times more effective at absorbing infrared radiation than are additional molecules of C02 (CFCs) already account for a quarter percent of the greenhouse forcing. A quadrupling of the CFCs is likely to result in an increase in temperature in from 0.5°C to 1.0°C.
Effects of Climate Change
Climate changes can severely affect human societies, agriculture and the natural ecosystem, Terrestrial and aquatic ecosystem, which provide many goods and services on which we rely, would be severely affected. Organisms and human infrastructure will not be able to adopt quickly and sufficiently to changed climatic effects. An ominous outcome of higher temperatures would be release of stores of methane hydrate now under permafrost in the Arctic. Combined with oxidation of high latitude peat lands, release of the carbon stores would add greatly to the C02 content in the atmosphere. Thus, the effects of warming themselves would cause more warming.
Many wild plant and animal species found today can be forced out of their present area of growth/habitats as climate warms. Many of them could adapt to the new conditions by migrating and other means but some would also die out. Climate change would impact on agricultural and forestry management in the sense that earlier spring planting of crops may be required and there would be alterations in forests due to fires and pests.
Rising sea levels and heavy storm damage would severely affect coastlines. Sea levels are increasing at about 2 mm per year. Thermal expansion alone can multiply that rate 5 times. A one meter rise in sea level over the 21st Century would mean submergence of some low-lying island nations and displacement of a large number of people – some 70 million people each in China and Bangladesh alone.
Infectious disease would become more common as global temperatures rise. Insect vectors would expand their ranges and become more active in areas they inhabit. Malaria, for instance, could spread from an area of 40% to 60% of the planet and it could arrive in new places like Nairobi in Kenya and Harare in Zimbabwe. Exposure to infections and diseases would be a result of heat, increase in UV radiation as well as pollutants like chlorinated hydrocarbons. The same elements associated with warming that add to the vitality of a disease may reduce human immunity to it by weakening our natural defenses.
By 2050, climate changes is expected to increase the risk of hunger by 10-20% compared to a no-climate change.
* Between 1980 and 2006, the number of climate related disasters has quadrupled.
* Climate change will effect two-thirds of the arable land in Africa could be lost by 2025.
* Approximately 600000 deaths accured worldwide as a result of weather related natural disasters in the 1990 some 95% of which took place in developing countries.
* More than half of world’s population lives within 60 km’s of shorelines. Rising sea level will directly impact them.
Certain observation recorded in India regarding climate change are given below
Decreasing trend of annual rainfall has been observed at Srinagar, Shimla, Mussoorie, Mukteshwar and Joshimath whereas increasing trend at Dehradun, Pauri, Nanital, Almora, Pithoragarh.
On seasonal scale, increasing trend of winter rainfall and summer rainfall, whereas decreasing trend of monsoon rainfall has been observed in Western Himalaya.
Decrease of snowfall and reduction in effective duration of winter has been observed in Pir Panjal Himalayan ranges.
Leh has experienced warming during last 100 years.
Number of heavy rainfall events are increasing almost over the entire landmass. Length of heat waves across India have extended in recent years, leading to warmer temperatures at right and hotter days.
Effects of Climate Change in India
» Coastal inundation and therefore resultant population displacement.
» Fall in crop yields resulting in food insecurity. It is estimated that every 1°C increase in temperature is likely to lead to a 5-10% reduction in yields of some crop.
» Increase in bacterial infection, vector borne disease and respiratory diseases.
1. Acid rain is formed due to contribution from the following pair of gases
(a) Methane and Ozone
(b) Oxygen and Nitrous oxide
(c) Methane and Sulphur dioxide
(d) Nitrogen oxides and Sulphur dioxide
2. Most serious environmental effect posed by hazardous waste is
(a) air pollution
(b) contamination of ground water
(c) increased use of land for landfils
(d) destruction of habitat
3. Which of the following is not a primary contribute to the greenhouse effect?
(a) Carbon dioxide
(b) Carbon mono oxide
(d) Methane gas
4. The increase in the concentration of C02 in our environment in last fifty years, since 1960 is about
5. How the biological oxygen demand gets affected with the increased presence of organic matter in water?
(a) The oxygen demand increases
(b) The oxygen demand decreases
(c) The oxygen demand remain unchanged
(d) None of the above
6. The headquarters of International Whaling Commission is located at
(a) New York
7. Increased defoliation in plants is caused by
(a) ozone depletion
(b) acid rains
(c) global wanning
(d) ground pollution
8. National Biodiversity Authority is located at
9. According to World Health Organisation which is the most polluted city in the world?
(a) Los Angeles, California
(b) Mexico City, Mexico
(c) New Delhi, India
(d) Shanghai, China
10. The best way to dispose plant waste is
11. Which among the following greenhouse gas has the highest radiative forces?
(a) Carbon dioxide
(c) Chlorofluoro carbons
12. Milankovitch cycles
(a) refer to shifts in the temperature of surface water in the middle latitudes of Pacific Ocean
(b) are changes in Earth’s rotation and orbit around the Sun that may trigger climate variation
(c) describe the timing of the Northern lights in the thermosphere
(d) describe upwelling and downwelling in the ocean
13. Keeling’s reports from Mauna Loa demonstrated
(a) an increase in Carbon dioxide from the 1950 to present
(b) that sediments deposited on the seafloor can yield dues about past climates
(c) Carbon dioxide gradient decreases from urban to rural
(d) the presence of El-Nino
14. Kyoto is to carbon dioxide as montreal is to
(a) living modified organisms
(b) persistent organic pollutants
(c) chlorofluoro carbons
15. Which of the following terms best applies to the practice of environ- mental science?
(a) Highly specialised
16. Salinisation occurs when the irrigation water accumulate in the soil evaporates, leaving behind salts and minerals. What are the effects of Salinisation on the irrigated land?
(a) It greatly increases the crop production
(b) It makes some soils impermeable
(c) It raises the water table
(d) It fills the air spaces in the soil
17. The Red data books published by the International Union for conservation of nature and national resources contain lists of
1. Endemic plant and animal species present in the biodiversity hot spots.
2. Threatened plant and animal species.
3. Protected sites for conservation of nature and natural resources in various countries.
Select the correct answer using the codes given below
(a) 1 and 3
(b) Only 2
(c) 2 and 3
(d) Only 3
18. Biodiversity forms the basis for human existence in the following ways
1. Soil formation
2. Preservation of soil erosion
3. Recycling of waste
4. Pollination of crops
Select the correct answer using the codes given below
(a) 1,2 and 3
(b) 2, 3 and 4
(c) land 4
(d) All of these
19. Which one of the following is not a site for in-site method of conservation of flora?
(a) Biosphere Reserve
(b) Botanical Garden
(c) National Park
(d) Wildlife Sanctuary
20. There is a concern over the increase in harmful, algal blooms in the sea waters of India. What could be the causative factors for this phenomena?
1. Discharge of nutrients from the Estuaries.
2. Run off from the land during the monsoon.
3. Upwelling in the seas.
Select the correct answer using the codes given below
(b) land 2
(c) 2 and 3
(d) All of these
21. Consider the following
3. Decay of organic matter
4. Volcanic action
Which of the above add carbon dioxide to the carbon cycle on the Earth?
(a) 1 and 4
(b) 2 and 3
(c) 2, 3 and 4
(d) All of these
22. A sandy and saline area in the natural habitat of an Indian animal species. The animal has no predators in that area but it’s existen is threatened due to the destruction of it’s habitat. Which one of the following could be that animal?
(a) Indian Wild Buffalo
(b) Indian Wild Ass
(c) Indian Wild Boar
(d) Indian Gazelle
23. Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of
1. its escape into the outer atmosphere.
2. the photosynthesis by Phytoplankton in the oceans.
3. the trapping of air in the polar ice caps.
Which of the statements given above is/are correct?
(a) 1 and 2
(b) Only 2
(c) 2 and 3
(d) Only 3
24. In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the
1. decomposed micro-organisms to the surface
2. nutrients to the surface
3. bottom-dwelling organism to the surface Which of the statements given above is/are correct?
(a) 1 and 2
(b) Only 2
(c) 2 and3
25. The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomena?
(a) It has a high rainfall that supports luxuriant vegetation
(b) It is a confluence of different bio geographical zones
(c) Exotic and invasive species have not been it introduced in this region
(d) It has less human interference
26. With reference to India, consider the following
1. import cud Export Control Act, 1947.
2. Mining and Mineral Development (regulation)Act. 1967.
3. Customs Act, 1962.
4. Indian Forest Act. 1927.
Which of the acts have relevance to bearing on the – biodiversity conservation into the country?
(a) 1 and 3
(b) 2. 3 and 4
(c) All of these
(d) None of these
27. Consider the following
1. Carbon dioxide
2. Oxides of Nitrogen
3. Oxides of Sulphur
Which of the above is/are the emission(s) from coal combustion zone at thermal power stations?
(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) 2 and 3
28. Microbial fuel cells are considered a source of sustainable energy. Why?
1. They use living organisms as catalysts to generate electricity from certain subststrates.
2. They use a variety of inorganic materials as substrates.
3. They can be installed in waste water treatment plants to cleanse water and produce electricity.
Which of the statements given above is/are correct?
(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) All of these
29. The formation of ozone hole in the Antarctica region has been a cause of concern, what could be the reason for the formation of this hole?
(a) Presence of prominent tropospheric turbulence and inflow of chlorofluoro carbons
(b) Presence of prominent polar front and stratospheric clouds and inflow of chlorofluoro carbons.
(c) Absence of polar front and stratospheric clouds and inflow of methane and chloro flouro carbons
(d) increased temperature at polar region due to global wanning
30. Regarding carbon credits, which one of the following statements is not correct?
(a) The carbon credit system was ratified in conjunction with the Kyoto protocol
(b) Carbon credits are awarded to countries or group that have reduced green house gases below their emission quota.
(c) The goal of the carbon credit system is to limit the increase of carbon dioxide emission.
(d) Carbon credits are traded at a price fined from time to time by United Nations Environment Programme
31. Mon-863 is a variety of maize. It was in the news from which one of the following reasons?
(a) It is genetically modified dwarf variety, which is resistant to drought
(b) It is genetically modified variety, which is pest resistant
(c) It is genetically modified variety with ten times higher protein content than regular maize crop
(d) It is a genetically modified variety used exclusively for bio-fuel production
32. Consider the following regions
1. Eastern Himalayas
2. Eastern Mediterranean region
3. North-West Australia
Which of the above is/are biodiversity hotspot(s)?
(a) Only 1
(b) 1 and 2
(c) 2 and 3
(d) All of these
33. Consider the following statements
1. Clean Development Mechanism (CDM) in respect of carbon credits is one of the Kyoto Protocol mechanisms.
2. Under the CDM, the projects handled pertain only to the Annex-1 countries.
Which of the statements given above is/ are correct?
(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2
34. Where was the world summit on sustainable development (Rio-10) held?
35. Out of all the Biosphere reserves in India, four have been recognised on the world network by UNESCO. Which one of the following is not one of them?
(a) Gulf of Mannar
(c) Nanda Devi
36. Which one among the following has the maximum numbers of National Park?
(a) Andaman and Nicobar Islands
(b) Arunachal Pradesh
37. Which one of the following Union Ministries is implementing the biodiesel mission (as nodal ministry)?
(a) Ministry of Agriculture
(b) Ministry of Science and Technology
(c) Ministry of New and Renewable Energy
(d) Ministry of Rural Development
38. Which one of the following is also known as Top slip?
(a) Simlipal National Park
(b) Periyar Wildlife Sanctuary
(c) Manjira Wildlife Sanctuary
(d) Indira Gandhi Wildlife Sanctuary and National Park
39. Which one of the following is located in Bastar region?
(a) Bandhavgarh National Park
(b) Randeli Sanctuary
(c) Rajaji National Park
(d) Indravati National Park
40. Which one of the following country is the first country in the world to propose a carbon tax for its people to address global warming?
(d) New Zealand
41. Consider the following statements about Kyoto Protocol came into force in the year 2005
1. Kyoto Protocol deals primarily with the depletion of ozone layer.
2. Methane as a greenhouse gas is more harmful than carbon dioxide.
Which of the above statements is/ are correct?
(a) 1 and 2
(b) 1 and 3
(c) Only 1
(d) Only 3
42. Match the following lists
43. Amongst the following Indian states, which one has minimum total forest cover?
44. Match the following lists
45. Genetic engineering approval commission, whose permission is required for cultivation of any genetically modified crop such as Bt-Cotton in India, is under Union Ministry of
(b) Environment and forest
(c) Commerce and industry
(d) Rural development
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